Battery tester



FIG. 1 is a front perspective view of a battery tester showing my new design;

FIG. 2 is a front elevational design thereof;

FIG. 3 is a rear elevational view thereof.

The broken-line showing of a battery in FIG. 1 is environmental only and forms no part of the claimed design. 

The ornamental design for a battery tester, as shown and described. 